Game device, game controlling method and program

ABSTRACT

A positional relationship between image capturing means and a player is properly adjusted before a game is started. An image of a player P is captured by a camera unit  42 , and from this image the head position of the player is recognized, so that the game proceeds based on the recognized result. At this time, the player image is displayed on the title screen, and the position where the head position of the player P should be located is displayed distinctively in the player image. As a result, the player P can properly adjust the positional relationship between the camera unit  42  and himself/herself before starting a game.

BACKGROUND OF THE INVENTION

The present invention relates to a game device, a game controllingmethod and a program. The present invention more particularly relates toa game device for providing a player with a game based on a result ofrecognizing a player image or the like acquired by image capturingmeans, and a game controlling method and a program therefor.

Arcade game machines having a camera unit located in front of a playerand proceeding with a game in accordance with a recognition result of aplayer image captured by the camera unit are well-known. Such a gamemachine can provide players with a much wider variety of games thanconventional game machines in which a controller is only operated withfingers.

However, implementing such a game machine for home-use causes thefollowing problem. For a home-use game machine the camera unit must beinstalled by a player, but it generally has a limited range forcapturing images. If the positional relationship between the camera andthe player is inappropriate, the player image cannot be recognizedproperly.

SUMMARY OF THE INVENTION

The present invention has been conceived in view of the above-describedproblem, and an object thereof is to provide a game device, a gamecontrolling method, and a program, capable of properly adjusting thepositional relationship between image capturing means and a player orthe like before starting a game.

In order to solve the above-described problem, a game device accordingto one aspect of the present invention comprises image capturing meansfor capturing player images, position recognizing means for recognizinga current position of a predetermined part of a player based on theplayer images captured by said image capturing means, game providingmeans for providing the player with a game based on the current positionof the predetermined part of the player recognized by said positionrecognizing means, and guiding means for guiding a standard position ofthe predetermined part of the player with respect to said imagecapturing means before provision of said game is initiated.

A game controlling method according to another aspect of the presentinvention comprises capturing player images by image capturing means,recognizing the player image captured by said image capturing means,providing a player with a game based on a recognized result, and guidinga standard position of a predetermined part of the player with respectto said image capturing means before provision of said game isinitiated.

A program according to a further aspect of the present invention causesa computer to execute capturing player images by image capturing means,recognizing the player image captured by said image capturing means,providing a player with a game based on a recognized result, and guidinga standard position of a predetermined part of the player with respectto said image capturing means before provision of said game isinitiated. The program according to the present invention may be storedin a variety of information storage media that can be read by thecomputer.

According to the present invention, player images are captured by imagecapturing means, and the current position of a predetermined part of aplayer is recognized based on the player images. A game is provided tothe player based on the recognized current position of the predeterminedpart of the player. At this time, the standard position of thepredetermined part of the player with respect to the image capturingmeans is guided before provision of the game is initiated. As a result,the positional relationship between the image capturing means and theplayer can be properly adjusted before starting the game.

According to one embodiment of the present invention, the guiding meansincludes player image displaying means for displaying the player imagecaptured by the image capturing means before provision of the game isinitiated, so that the player can properly adjust the positionalrelationship between the image capturing means and himself/herself whilewatching the player image.

In this embodiment, the guiding means may further include standardposition displaying means for displaying an image indicating thestandard position of the predetermined part of the player to besuperposed on the player image displayed by the player image displayingmeans. Such a configuration enables the player to properly adjust thepositional relationship between the image capturing means andhimself/herself by aligning the predetermined part of the player in theplayer image with the image indicating the standard position.

The guiding means may further include recognized result displaying meansfor displaying an image indicating the current position of thepredetermined part of the player recognized by the position recognizingmeans to be superposed on the player image displayed by the player imagedisplaying means. As a result, the player can properly adjust thepositional relationship between the image capturing means andhimself/herself by confirming the displayed position of the imageindicating the current position of the predetermined part.

Further, according to another embodiment of the present invention, theguiding means further includes reporting means for reporting to theplayer that the current position of the predetermined part of the playerrecognized by the position recognizing means is located at the standardposition of the predetermined part of the player with respect to theimage capturing means when the current position is located at such aposition. Such a configuration enables the player to properly adjust thepositional relationship between the image capturing means andhimself/herself by confirming the reported content.

A game device according to a further aspect of the present inventioncomprises image capturing means for capturing images, positionrecognizing means for recognizing a current position of an object basedon the images captured by the image capturing means, game providingmeans for providing a player with a game based on the current positionof the object recognized by the position recognizing means, and guidingmeans for guiding a standard position of the object with respect to theimage capturing means before provision of the game is initiated.

Further, a game controlling method according to a further aspect of thepresent invention comprises capturing images by image capturing means,recognizing a current position of an object based on the images capturedby the image capturing means, providing a player with a game based on arecognized result, and guiding a standard position of the object withrespect to the image capturing means before provision of the game isinitiated.

A program according to a further aspect of the present invention causesa computer to execute capturing images by image capturing means,recognizing a current position of an object based on the images capturedby the image capturing means, providing a player with a game based on arecognized result, and guiding a standard position of the object withrespect to the image capturing means before provision of the game isinitiated.

According to the present invention, an image of an object is acquired byimage capturing means, and a current position of the object isrecognized based on the image. The object is something whose positionaffects a game, such as a certain part of a player's body, an article inthe player's hand, or the like. The game is provided to the player basedon the recognized current position of the object. At this time, thestandard position of the object with respect to the image capturingmeans is guided before provision of the game is initiated. As a result,the positional relationship between the image capturing means and theobject can be properly adjusted before starting the game.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a player enjoying a gun shooting game using a gamedevice according to an embodiment of the present invention.

FIG. 2 illustrates an example of a title screen (start screen).

FIGS. 3A-3D are views for explaining an exemplary game screen presentedwhen the player moves vertically.

FIGS. 4A-4D are views for explaining an exemplary game screen presentedwhen the player moves horizontally.

FIG. 5 is a diagram illustrating a hardware configuration of the gamedevice.

FIG. 6 is a flowchart for explaining a process for displaying the titlescreen.

FIG. 7 illustrates an example of a player's standing position guidanceimage included in the title screen.

FIGS. 8 and 9 illustrate variations of a player's standing positionguidance image included in the title screen.

FIG. 10 is a flowchart for explaining a player image processing.

FIG. 11 is a flowchart for explaining a process of filtering arecognized position.

FIGS. 12A-12D illustrate a series of player images.

FIG. 13 is a view illustrating a difference image between an averagedplayer image and the latest player image.

FIG. 14 is a view illustrating the result of extracting a region in thevicinity of the previously recognized position from the imageillustrated in FIG. 13.

FIG. 15 is a view illustrating a difference image between the averagedplayer image and the latest player image when the player makes a smallmovement.

FIG. 16 is a view illustrating the result of extracting a region in thevicinity of the previously recognized position from the imageillustrated in FIG. 15.

FIG. 17 is a view illustrating a difference image between the latestplayer image and the immediately preceding player image.

FIG. 18 is a view illustrating the result of extracting a region in thevicinity of the previously recognized position from the imageillustrated in FIG. 17.

FIG. 19 is a view illustrating a difference image between the latestplayer image and the immediately preceding player image when thepreviously recognized position is distant from the latest player imageand the immediately preceding player image.

FIG. 20 is a view illustrating the result of extracting, from the imageillustrated in FIG. 19, the area moved closer to the player from thepreviously recognized position.

FIGS. 21A and 21B illustrate the content stored in the recognizedposition buffer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The entire disclosure of the corresponding Japanese application2001-199002 filed on Jun. 29, 2001 including specification, claims,drawings and summary, is incorporated herein by reference.

Exemplary embodiments of the present invention will now be described indetail with reference to the drawings.

FIG. 1 is a perspective view for expressing a situation where a playerplays a game using a game device according to one embodiment of thepresent invention. As illustrated in FIG. 1, the game device, whichincludes a home-use TV receiver 40, a camera unit 42, a home-use gamemachine 46, and a gun controller 48, is used for implementing a gunshooting game. The home-use TV receiver 40 and the home-use game machine46 are mounted on a cabinet 44, while the camera unit 42 is on thehome-use TV receiver 40. The camera unit 42 is a digital camera forpresenting an image of a player P in real time, and connected to thehome-use game machine 46 via a cable for supplying the captured playerimage to the game machine 46 in real time. The home-use game machine 46is connected to the home-use TV receiver 40, so that game screen imagesproduced by the game machine 46 are displayed while providing game musicor game effect sound. The gun controller 48 is a game controller in theform of a gun, and connected to a controller connection terminal of thehome-use game machine 46 via a cable. When the player P holds the guncontroller 48 in his/her hand and aims it at the home-use TV receiver40, the direction of its gun barrel is input to the home-use gamemachine 46. The gun controller 48 is provided with a trigger, whosecondition (i.e. whether or not the trigger is pulled) is supplied to thehome-use game machine 46.

In the home-use game machine 46, a three-dimensional game space (virtualthree-dimensional space) is constructed in a memory, and how thethree-dimensional game space is viewed from a viewpoint disposed at apredetermined spatial position is displayed on the TV receiver 40. Atthis time, in the home-use game machine 46, the position of the head ofthe player P is recognized from the player image, and the position ofthe viewpoint moves with the head position. As a result, when the playerP moves his/her body in front of the camera unit 42, the game screenimage displayed on the home-use TV receiver 40 is changed in accordancewith the movement, so that the player P can feel as if he/she enteredthe three-dimensional game space. Thus, the home-use game machine 46implements a game in which the player P shoots an enemy game characterappearing in the three-dimensional game space with the gun controller48, and avoids attacks (shooting) from the enemy game character bymoving his/her body (specifically, the head position).

FIG. 2 illustrates an example of a title screen (start screen) of thegame provided by the home-use game machine 46. The title screen in thisfigure is presented on the home-use TV receiver 40 after the home-usegame machine 46 is activated or between games. As illustrated, on thistitle screen, menu button images 62 are displayed at either side of thescreen, and a character string 60 indicating the title of the game isdisplayed at an upper central portion. Under the title character string60, an image 50 for guiding the position where the player stands isdisplayed. The menu button images 62 are targets used for proceeding toa variety of games or option setting. When the player P shoots the menubutton image 62 with the gun controller 48, the game or option settingcorresponding to the shot menu button image 62 is initiated.

The player's standing position guidance image 50 is used for helping theplayer P to properly adjust the position where he/she stands beforestarting a game. The player P adjusts his/her standing position orposture in front of the camera unit 42, or adjusts the image capturingdirection or position of the camera unit 42 before the game is started.The image 50 is obtained by displaying a head standard position marker52 and a current recognized position marker 54 superposed on the baseimage, that is, the image captured by the camera unit 42 in real time,i.e. a player image 56. The head standard position marker 52 is acircular marker displayed at a fixed position of the player image 56(such as the central position of the player image 56 located 15% fromthe top), and used for indicating the position (standard position) withwhich the image of (the uppermost part of) the player's head in theplayer image 56 should be aligned before the game is started. This gamedevice 10 is designed such that the current position of the head of theplayer P can be recognized from the player image 56, and a dotindicating the recognized position is displayed superposed on the playerimage 56 as the current recognized position marker 54. The player Pmoves his/her body (the standing position or the posture) or changes theimage capturing direction or position of the camera unit 42 so that thecurrent recognized position marker 54 is placed within the circular headstandard position marker 52, thereby properly adjusting the standardposition (initial playing position). At this time, the game device 10determines whether or not the current recognized position marker 54 isdisplayed within the head standard position marker 52, and changes themanner of displaying the head standard position marker 52 (such as coloror blinking indication) in accordance with the determined result. Thus,the player P can easily carry out proper adjustment of the positionalrelationship between the player and the camera unit 42 while watchingthe player's standing position guidance image 50 before starting a game.

FIGS. 3A-3D illustrate an example of a series of game screens presentedon the home-use TV receiver 40 when the head of the player P moves inthe vertical direction. The figures show four screen images in thedisplayed order when the player P gradually rises from a half-sittingposture to a substantially erect posture in front of the camera unit 42,i.e. when the head of the player P is raised from a lower position to ahigher position. The game screen in FIG. 3A includes a desk-shapedobstacle B immediately in front of the viewpoint, indicating that theplayer P is hiding in front of and below the obstacle B. In thissituation, only part of the head of an enemy game character AC1 locatedbeyond the obstacle B and holding a gun in his hand is displayed on thegame screen. The game screen in FIG. 3B represents the situation wherethe player P raises his/her head a little so that the head is positionedsubstantially flush with the upper surface of the obstacle B. In such asituation, the enemy game character AC1 is displayed up to the chestthereof on the game screen, and the heads of two more enemy gamecharacters AC2 and AC3 are additionally displayed behind the characterAC1. The game screen illustrated in FIG. 3C indicates the situationwhere the player P further stretches his/her back to raise his/her head.In such a situation, the head of the player P is located slightly higherthan the upper surface Bs of the obstacle, and upper bodies of the threeenemy characters AC1-AC3 and the upper surface Bs of the obstacle aredisplayed. The game screen illustrated in FIG. 3D indicates thesituation where the player P is in a substantially erect posture. Inthis situation, the player is exposed approximately up to the neck fromthe obstacle B, and the upper surface Bs of the obstacle is displayedmore widely than that in the game screen of FIG. 3C. As illustrated inthese figures, as the player's head is raised, the position where theobstacle B is displayed moves downward, and the upper surface Bs of theobstacle and the enemy game characters AC1-AC3 are gradually displayedon the game screen to reveal the whole images thereof.

FIGS. 4A-4D illustrate an example of a series of game screens presentedon the home-use TV receiver 40 when the head of the player P movessideways. FIGS. 4A-4D show four screen images in the displayed orderwhen the player P moves his/her body from right to left in front of thecamera unit 42, i.e. the head of the player P moves from right to left.The game screen in FIG. 4A includes the obstacle B in the form of a dooror a wall located on the right and immediately in front of theviewpoint, indicating the situation where the player P is hiding infront of the obstacle B. In such a situation, only part of an arm of theenemy game character AC1 located beyond the obstacle B and holding a gunin his hand is displayed on the game screen. The game screen in FIG. 4Brepresents the situation where the player P moves slightly to the leftso that his/her head is substantially flush with the left edge of theobstacle B, showing up to the head and chest of the enemy game characterAC1. The game screen in FIG. 4C represents the situation where theplayer P moves further to the left, showing substantially the upper halfof the enemy game character AC1 and the enemy game character AC2 behindthe character AC. The game screen in FIG. 4D represents the situationwhere the player P comes out from the obstacle B to the left. In thissituation, the enemy game character AC3 is also displayed in addition tothe enemy game characters AC1 and AC2. As illustrated in these figures,as the player's head moves from left to right, the displayed position ofthe obstacle B moves rightward and the enemy game characters AC1-AC3gradually appear on the game screen to reveal the whole images thereof.

FIG. 5 illustrates a hardware configuration of the game device 10. Asillustrated, the game device 10 is formed by a DVD™ (digital versatiledisk) 25, which is an information storage medium, placed in the home-usegame machine 46 connected to the monitor 18 and the speaker 22. Whilethe DVD 25 is used for supplying a game program and game data to thehome-use game machine 46 in this embodiment, any other informationstorage media, such as CD-ROMs (compact disk-read only memory) and ROM(read only memory) cards, may be used instead. The game program and thegame data can be remotely supplied to the home-use game machine 46through a data network such as Internet.

The home-use game machine 46 includes a microprocessor 14, an imageprocessing unit 16, a main memory 26, and an input/output processingunit 30, a peripheral equipment interface 31, a sound processing unit20, and a DVD reproducing unit 24. The microprocessor 14, the imageprocessing unit 16, the main memory 26, the input/output processing unit30, and the peripheral equipment interface 31 are mutually connected viaa bus 12 for data exchange, with the input/output processing unit 30being further connected to the gun controller 48, the sound processingunit 20, and the DVD reproducing unit 24. The peripheral equipmentinterface 31 is connected to the camera unit 42. The respective elementsof the home-use game machine 46 are all accommodated in a housing. Inthis embodiment, the home TV receiver 40 is used as the monitor 18, anda speaker incorporated therein is used as the speaker 22.

The microprocessor 14 controls the respective elements of the home-usegame machine 46 based on an operating system stored in an unillustratedROM and the game program read from the DVD 25. The bus 12 is used forexchanging addresses and data among the respective elements of thehome-use game machine 46. The main memory 26 is used for storing thegame program and game data read from the DVD 25 as required. The imageprocessing unit 16, which includes a VRAM (video random access memory),receives image data from the microprocessor 14, and draws a game screenimage in the VRAM. The image processing unit 16, moreover, converts thecontent of the VRAM into a video signal provided to the monitor 18.

The input/output processing unit 30 is an interface for relaying datacommunication between the microprocessor 14 and the gun controller 48,the sound processing unit 20, and the DVD reproducing unit 24. The guncontroller 48 is a game controller in the form of a gun, as illustratedin FIG. 1, used for providing the home-use game machine 46 with atrigger state and the direction of the gun barrel or muzzle(specifically, the pointed position on the screen of the home-use TVreceiver 40). The gun controller 48 can be of, for example, a well-knownstructure. More specifically, the gun controller 48 is designed so that,when the player P pulls a trigger of the gun controller 48, suchinformation (trigger signal) is supplied from a controller terminal tothe home-use game machine 46. When the home-use game machine 46 receivesthe trigger signal, an illuminating spot is scanned on the screen of thehome-use TV receiver 40 by causing the game program to, for example,present a white screen for a single frame. The gun controller 48 isdesigned to include a light-receiving sensor with strong directivity atthe back of the gun muzzle, so that, when the illuminating spot on thehome-use TV receiver 40 is detected by the light-receiving sensor, thetime period between the start of scan and the detection of theilluminating spot is calculated, thereby obtaining the position(coordinates) of the spot on the screen of the TV receiver 40 from thetime period thus calculated. The position, i.e. the direction of the gunbarrel, is supplied to the home-use game machine 46. Thus, the guncontroller 48 can be suitably implemented. The time when scanning isstarted can be preferably obtained from a synchronous signal included ina video signal which is supplied from the home-use game machine 46 tothe home-use TV receiver 40.

The sound processing unit 20 includes a sound buffer, and reproducesdata, such as music and game effect sound read by the DVD 25 and storedin the sound buffer, and outputs the data from the speaker 22. The DVDreproducing unit 24 reads the game program and game data recorded in theDVD 25 in accordance with an instruction from the microprocessor 14. Theperipheral equipment interface 31 is an interface for connecting avariety of peripheral devices to the home-use game machine 46, and canbe formed by a USB (universal serial bus) interface or the like. In thisembodiment, the camera unit 42 is connected to the peripheral equipmentinterface 31. The camera unit 42 is, for example, a well-known digitalcamera for supplying to the home-use game machine 46 a captured grayscale image (256 levels of gray) at predetermined time intervals (suchas 1/60 seconds). In order to capture the image of the player P, thecamera unit 42 is mounted on the home-use TV receiver 40 with its lensfacing the player P in this embodiment. The process performed by thehome-use game machine 46 for displaying a title screen will now bedescribed. This process is performed based on the game program stored inthe DVD 25.

FIG. 6 is a flowchart for describing a process of displaying a titlescreen by the home-use game machine 46. As illustrated, in the home-usegame machine 46, the microprocessor 14 first draws a background image ofthe title screen, a character string of the title 60, the menu buttonimage 62, a copyright message, and the like in a VRAM included in theimage processing unit 16 (S101). An image captured by the camera unit 42(hereinafter referred to as a “player image” because capturing the imageof the player P is intended) is acquired (S102). The player imageacquired at the step S102 is drawn in the VRAM so that the player imageis placed where the player's standing position guidance image 50 islocated in the title screen (S103).

The position of the head of the player P (head position) is recognizedbased on the player image acquired at the step S102, and informationobtained by filtering the recognition result (filtered head position) isacquired (S104). The process of recognizing the position and filteringwill be described later. The microprocessor 14 then draws the currentrecognized position marker 54 at the coordinates of the VRAMcorresponding to the filtered head position so that the marker (redspot) is displayed at the head position of the player image included inthe title screen (S105).

The microprocessor 14 then determines whether or not the filtered headposition is located at the standard position (in the reference area).The standard position is the position in the player image where the headof the player P should be located before a game is started. If thefiltered head position is located at the standard position, a red headstandard position marker 52 is drawn at the standard position of theplayer image (S107). On the other hand, if the filtered head position isnot at the standard position, a blue head standard position marker 52 isdrawn at the standard position of the player image (S108). Next, thedirection of the barrel of the gun controller 48 is acquired (S109), andat this position an aiming marker 58 is drawn (S110).

Thus, when the positional relationship between the player P and thecamera unit 42 is inappropriate, the currently recognized positionmarker 54 is displayed outside the circular head standard positionmarker 52, which is displayed in blue, on the title screen asillustrated in FIG. 7. On the other hand, when the positionalrelationship between the player P and the camera unit 42 is appropriate,the currently recognized position marker 54 is displayed inside thecircular head standard position marker 52, which is displayed in red, onthe title screen. As a result, the player P can change the standingposition or the position where the camera unit 42 is installed or theimage capturing direction to cause the head standard position marker 52to be displayed in red on the title screen, thereby easily adjusting thepositional relationship between the player P and the camera unit 42.

If the positional relationship between the player P and the camera unit42 is not properly adjusted, the position of the head will not be placedwithin the player image when the player P bends down or sways during thegame, causing possible misrecognition of the head position. However,according to the present game device 10, the positional relationshipbetween the player P and the camera unit 42 can be properly adjustedbefore starting a game, so that the head position can be correctlyrecognized even when the player P bends down or sways during the game.

The guidance provided to the player P is not limited to that describedabove. For example, as in the guidance image illustrated in FIG. 8, itis possible to display only the current recognized position marker 54and the head standard position marker 52 without displaying the playerimage. Instead of changing the manner of displaying the head standardposition marker 52 based on the positional relationship between thecurrent recognized position marker 54 and the head standard positionmarker 52, the manner of displaying the current recognized positionmarker 54 (such as color or blinking pattern) may be changed.Alternatively, display may be presented at another position based on thepositional relationship between the current recognized position marker54 and the head standard position marker 52. Further, the currentrecognized position marker 54 may not be displayed.

Further, as in the guidance image illustrated in FIG. 9, only thecurrent recognized position marker 54 may be displayed, and the mannerof displaying the marker 54 may be changed when the marker 54 is movedto the position where the head standard position marker 52 indicated bya dashed line in FIG. 9 should be displayed (the circle indicated by thedashed line in the figure is not actually displayed on the screen). Inthis manner as well, the player P can correct the positionalrelationship between the camera unit 42 and himself/herself whilewatching the guidance image.

Alternatively, messages, such as “Move to the right”, “Move to theleft”, “Move forward”, and “Move backward”, may be displayed based onthe relationship between the standard position and the currentlyrecognized position of the head of the player P. Further, the shapes ofthe current recognized position marker 54 and the head standard positionmarker 52 are not limited to those described above, and a variety ofshapes are possible. The guidance is preferably provided to the player Pbefore the game is started, and therefore the guidance for the player Pmay be provided, for example, on a screen different from the titlescreen.

The process performed on the player image in the home-use game machine46 will next be described.

FIG. 10 is a flowchart for describing a process for recognizing the headposition of the player P based on the player image captured by thecamera unit 42 and filtering the recognized result. FIG. 11 is aflowchart for describing the filtering process in detail. Theseprocesses are performed in the home-use game machine 46 at predeterminedtime intervals (such as 1/60 of a second) based on the game programstored in the DVD 25.

When the player image is captured by the camera unit 42, themicroprocessor 14 first stores the player image in an image bufferprovided in the main memory 26, as shown in FIG. 10 (S201). The imagebuffer is used for storing the player image captured by the camera unit42 at predetermined time intervals, and stores a predetermined number (atotal of four in this embodiment) of player images including the latestimage in time sequence. When the latest player image is acquired, thenewly acquired player image is additionally stored in the image bufferand the oldest player image is deleted. FIGS. 12A-12D show an example ofa series of player images stored in the image buffer. FIG. 12A shows thelatest player image, FIG. 12B shows the immediately preceding playerimage, FIG. 12C shows the player image immediately preceding the imagein FIG. 12B, and FIG. 12D shows the player image immediately precedingthe image in FIG. 12C, i.e. the oldest image in the image buffer. Inthis example of FIGS. 12A-12D, the player P swings from left to right infront of the camera unit 42.

The microprocessor 14 then produces an averaged image of three playerimages stored in the image buffer excluding the latest image (S202). Theaveraged image is obtained by averaging the respective color information(256 levels of gray) assigned to the corresponding pixels of the threeplayer images. The microprocessor 14 then produces a difference betweenthe averaged image and the latest player image (S203). The differenceimage is produced by binarizing (monochroming) the image obtained bysubtraction of color information assigned to the corresponding pixels ofthe two images. FIG. 13 shows an example of such a difference image. Animage located within a circle centered at the previously recognizedposition (the head position of the player P) with a predetermined radiusis extracted from the difference image (S204). FIG. 14 shows an exampleof the extracted image. In the figure, the black dot indicates thepreviously recognized position, which is not displayed in the extractedimage in practice.

The microprocessor 14 then determines whether or not the area of theregion displayed in black in the extracted image (the region where adifference remains) is smaller than a predetermined threshold (S205). Ifthe area of the black region in the extracted image is smaller than thepredetermined threshold, the previous output prestored in the mainmemory 26 (filtered head position) is output again (S213). When theplayer P does move very much, the difference remains only at the contourof the player P in the difference image obtained at the step S203 asillustrated in FIG. 15. In such a case, by extracting the vicinity ofthe previously recognized position the area is reduced as illustrated inFIG. 16. In the process from the step S202 to the step S205, theprevious output is thus provided again when the player P makes only asmall movement, so that fluctuation in output value is suppressed.

On the other hand, if the area of the black region in the extractedimage is equal to or exceeds the predetermined threshold, the latestplayer image (FIG. 12A) and the immediately preceding player image (FIG.12B) are read from the image buffer to produce the difference image(binarized image) (S206). FIG. 17 shows an example of such a differenceimage. The microprocessor 14 then extracts an image within a circlecentered at the previously recognized position with a predeterminedradius (selection range) from the difference image. FIG. 18 shows anexample of the extracted image. In FIG. 18, the black dot indicates thepreviously recognized position, and is not displayed in the extractedimage in practice. The position of the pixel displayed in black in theextracted image is used for recognizing the head position of the playerP at the step S211. In other words, the extracted image includes a baseposition group for recognizing the head position of the player P.

The microprocessor 14 measures the height and width of the black regionin the extracted image (the base position group, i.e. the region where adifference remains), and determines whether or not the values aresmaller than the respective predetermined thresholds (S208). If eithervalue is smaller than the predetermined threshold, the extracted range(selection range) is shifted toward the player P and reproduces theextracted image (S210) until the extracted range (selection range) issufficiently close to the player P (S209). More specifically, thebarycenter of the region shown in black in the difference image(binarized image) obtained at the step S206 is calculated, and thecenter of the extracted range (selection range) is moved closer to thebarycenter from the previously recognized position by a predetermineddistance at a time. FIG. 19 is a view for explaining such a process. Theregion with hatching indicates a region where the difference remains, ablack triangle indicates the barycenter of the difference, and a blackdot indicates the previously recognized position. This figure shows thatthe player P has rapidly moved in front of the camera unit 42 from theupper left to the lower right. In such a situation, the center of theextracted range (selection range) is gradually moved from the black dotposition toward the black triangle in the figure at the step S210. Ifthe black region in the extracted image is still small even aftermovement is made by a predetermined ratio, such as 70%, of the distancebetween the previously recognized position and the barycenter, theprevious output is supplied again (S213). On the other hand, if both theheight and width of the black region in the extracted image are equal toor exceed the predetermined threshold as illustrated in FIG. 20 aftershifting the extracted range (selection range), the head position ofinterest is determined from that particular extracted image (S211). Forexample, the position located at the center of the black region andseveral pixels from the top in the extracted image is selected as thehead position of interest. The current head position thus selected(recognized) is filtered to supply a filtered head position (S212).

Thus, the base position group is selected within the selection rangecorresponding to the previously recognized position in principle, andreselected by changing the selection range exceptionally, therebyeliminating effects of moving objects, if any, other than the playerappearing in the player image and achieving proper recognition of theposition even when the head position rapidly moves.

In the above-described filtering process, a head position buffer isprovided in the main memory 26 for storing a maximum of 16 headpositions (P_(n) to P_(n−15) wherein the index corresponds to the timeof recognition) as illustrated in FIG. 21A. The head position buffer isused for storing the head position of the player P recognized atpredetermined intervals. In this buffer, a maximum of 16 head positionsare stored in time sequence including the latest head position. When thelatest head position is recognized, this head position is additionallystored in the head position buffer, and the oldest head position isdeleted. When, for example, the head position P_(n+1) is recognizedwhile the buffer is in the state illustrated in FIG. 21A, the headposition P_(n+1) is additionally stored and the oldest head positionP_(n−15) is deleted from the head position buffer. The buffer size ofthis head position buffer, i.e. the number of head positions storedtherein, is variable, and therefore assumes one of four states in whichthe number of stored head positions is two as in FIG. 21B, four, eight,or sixteen as in FIG. 21A.

As illustrated in FIG. 11, the filtering process begins with acquisitionof the current buffer size n of the head position buffer (S301). If thecurrent buffer size n is equal to the maximum size Nmax (16 in thisexample) (S302), the oldest head position is deleted from the headposition buffer, and the latest head position is stored in the headposition buffer (S305). On the other hand, if the current buffer size nis not equal to the maximum size Nmax, the latest head position isadditionally stored in the head position buffer without deleting theoldest head position (S303), and adds one to the current buffer size n(S304).

The amount of movement for each head position stored in the headposition buffer is next calculated (S306). More specifically, thedistance between each head position and the immediately previous headposition is obtained. For instance, in the example of FIG. 21, thedistances between the head positions P_(n) and P_(n−1), between the headpositions P_(n−1) and P_(n−2), between the head positions P_(n−2) andP_(n−3), . . . , and between the head positions P_(n−14) and P_(n−15)are calculated. An average of the thus calculated movement amounts isobtained to determine the buffer size N corresponding to the average(S307). By way of example, the buffer size N is defined here as 2 whenthe average is not smaller than 11, 4 when the average is 9 or greaterbut smaller than 11, 8 when the average is 7 or greater but smaller than9, and 16 when the average is smaller than 7. While the buffer size N isdetermined based on the averaged movement amount of the respective headpositions stored in the head position buffer in this embodiment, othercalculation methods may be used instead. For example, the movementamounts of the respective head positions may be weighted, or only therelatively new head positions among those stored in the head positionbuffer may be subjected to calculation of movement amount, so that thebuffer size N can be rapidly reduced when the latest head position isdetermined as being rapidly moved.

Next, the current buffer size n and the buffer size N are compared(S308). If the current buffer size n exceeds the buffer size N, the headpositions stored in the head position buffer are deleted starting fromthe oldest one in time sequence until the current buffer size n is equalto the buffer size N (S309). On the other hand, if the current buffersize n is equal to or smaller than the buffer size N, the step S309 isskipped. The average of the head positions stored in the head positionbuffer is obtained and stored in the main memory 26 as the previousoutput (S311), and output as the filtered head position (S312). Thefiltered head position thus output is used for determining the viewpointposition when a three-dimensional game space is drawn, as describedabove. The filtered head position is also used for determining thedisplay position of the currently recognized position marker 54 when theplayer's standing position guidance image 50 is displayed on the titlescreen. Note that although the average of the head positions stored inthe head position buffer is used as the filtered head position in theabove description, the head positions stored in the head position buffermay be weighted, so that, for example, the latest head position gives agreater effect on the filtered head position.

According to the above-described filtering process, the average of thehead positions stored in the head position buffer is output, therebyreducing fluctuation in the value of the filtered head position.Further, as the size of the head position buffer, i.e. the number ofstored positions is varied in accordance with the movement amounts ofthe respective head positions stored in the head position buffer, thevalue of the filtered head position can be rapidly changed to cope witha rapid movement of the head position of the player P. As a result, thegame process using the filtered head position can be properly performed.

The present invention is not limited to the above-described embodiment.

For example, while the present invention is applied to a gun shootinggame in the above description, it is applicable to any kind of gamesthat proceed based on an image captured by the image capturing means.

Although the head of the player P is the object for position recognitionin the above description, any other parts can be such objects. Further,the object can be a variety of articles the player holds in his/herhands, such as a toy golf club, a toy tennis racket, a toy weapon, andthe like.

1. A game device, comprising: image capturing means for capturing playerimages; position recognizing means for recognizing a current position ofa predetermined part of a player based on the player images captured bysaid image capturing means; game providing means for providing theplayer with a game based on the current position of the predeterminedpart of the player recognized by said position recognizing means; andguiding means for guiding a standard position of the predetermined partof the player with respect to said image capturing means beforeprovision of said game is initiated, wherein said guiding meanscomprises: player image displaying means for displaying the player imagecaptured by said image capturing means before provision of said game isinitiated, standard position displaying means for displaying an imageindicating the standard position of the predetermined part of theplayer, and recognized result displaying means for displaying an imageindicating the current position of the predetermined part of the playerrecognized by said position recognizing means.
 2. A game deviceaccording to claim 1, wherein said standard position displaying meansdisplays the image indicating the standard position of the predeterminedpart of the player superposed on the player image displayed by saidplayer image displaying means.
 3. A game device according to claim 1,wherein said recognized result displaying means displays the imageindicating the current position of the predetermined part of the playerrecognized by said position recognizing means superposed on the playerimage displayed by said player image displaying means.
 4. A game deviceaccording to claim 1, wherein said guiding means further includesreporting means for reporting to the player that the current position ofthe predetermined part of the player recognized by said positionrecognizing means is located at the standard position of thepredetermined part of the player with respect to said image capturingmeans when said current position is located at such a position.
 5. Agame controlling method, comprising steps of: capturing player images byimage capturing means; recognizing a current position of a predeterminedpart of the player based on the player image captured by said imagecapturing means; providing a player with a game based on a recognizedresult; and guiding a standard position of the predetermined part of theplayer with respect to said image capturing means before provision ofsaid game is initiated, wherein said guiding comprises: displaying theplayer image captured by said image capturing means before provision ofsaid game is initiated, displaying an image indicating the standardposition of the predetermined part of the player, and displaying animage indicating the current position of the predetermined part of theplayer recognized by said position recognizing means.
 6. A computerreadable medium having recorded thereon a program for causing a computerto execute steps of: capturing player images by image capturing means;recognizing a current position of a predetermined part of the playerbased on the player image captured by said image capturing means;providing a player with a game based on a recognized result; and guidinga standard position of the predetermined part of the player with respectto said image capturing means before provision of said game isinitiated, wherein said guiding comprises: displaying the player imagecaptured by said image capturing means before provision of said game isinitiated, displaying an image indicating the standard position of thepredetermined part of the player, and displaying an image indicating thecurrent position ot the predetermined part of the player recognized bysaid position recognizing means.
 7. A game device, comprising: imagecapturing means for capturing images; position recognizing means forrecognizing a current position of an object based on the images capturedby said image capturing means; game providing means for providing aplayer with a game based on the current position of the objectrecognized by said position recognizing means; and guiding means forguiding a standard position of the object with respect to said imagecapturing means before provision of said game is initiated, wherein saidguiding means comprises: image displaying means for displaying the imagecaptured by said image capturing means before provision of said game isinitiated, standard position displaying means for displaying an imageindicating the standard position of the object, and recognized resultdisplaying means for displaying an image indicating the current positionof the object recognized by said position recognizing means.
 8. A gamecontrolling method, comprising steps of: capturing images by imagecapturing means; recognizing a current position of an object based onthe images captured by said image capturing means; providing a playerwith a game based on a recognized result; and guiding a standardposition of the object with respect to said image capturing means beforeprovision of said game is initiated, wherein said guiding comprises:displaying the image captured by said image capturing means beforeprovision of said game is initiated, displaying an image indicating thestandard position of the object, and displaying an image indicating thecurrent position of the object recognized by said position recognizingmeans.
 9. A computer readable medium having recorded thereon a programfor causing a computer to execute steps of: capturing images by imagecapturing means; recognizing a current position of an object based onthe image captured by said image capturing means; providing a playerwith a game based on a recognized result; and guiding a standardposition of the object with respect to said image capturing means beforeprovision of said game is initiated, wherein said guiding comprises:displaying the image captured by said image capturing means beforeprovision of said game is initiated, displaying an image indicating thestandard position of the object, and displaying an image indicating thecurrent position of the object recognized by said position recognizingmeans.
 10. A game device according to claim 2, wherein said recognizedresult displaying means displays the image indicating the currentposition of the predetermined part of the player recognized by saidposition recognizing means superposed on the player image displayed bysaid player image displaying means.
 11. A game device according to claim1, wherein said guiding means further includes reporting means forreporting to the player that the current position of the predeterminedpart of the player recognized by said position recognizing means islocated at the standard position of the predetermined part of the playerwith respect to said image capturing means when said current position islocated at such a position.
 12. A game device according to claim 2,wherein said guiding means further includes reporting means forreporting to the player that the current position of the predeterminedpart of the player recognized by said position recognizing means islocated at the standard position of the predetermined part of the playerwith respect to said image capturing means when said current position islocated at such a position.
 13. A game device according to claim 3,wherein said guiding means further includes reporting means forreporting to the player that the current position of the predeterminedpart of the player recognized by said position recognizing means islocated at the standard position of the predetermined part of the playerwith respect to said image capturing means when said current position islocated at such a position.
 14. A game device according to claim 10,wherein said guiding means further includes reporting means forreporting to the player that the current position of the predeterminedpart of the player recognized by said position recognizing means islocated at the standard position of the predetermined part of the playerwith respect to said image capturing means when said current position islocated at such a position.
 15. The game device according to claim 1,wherein said guiding means comprises guiding the player to adjust thecurrent position of the predetermined part of the player to the standardposition of the predetermined part of the player with respect to saidimage capturing means before the provision of said game is initiated.16. The game controlling method according to claim 5, wherein saidguiding comprises guiding the player to adjust a current position of thepredetermined part of the player to the standard position of thepredetermined part of the player with respect to said image capturingmeans before the provision of said game is initiated.
 17. The computerreadable medium according to claim 6, wherein said guiding comprisesguiding the player to adjust a current position of the predeterminedpart of the player to the standard position of the predetermined part ofthe player with respect to said image capturing means before theprovision of said game is initiated.
 18. The game device according toclaim 7, wherein said guiding means comprises guiding the player toadjust the current position of the object to the standard position ofthe object with respect to said image capturing means before theprovision of said game is initiated.
 19. The game controlling methodaccording to claim 8, wherein said guiding comprises guiding the playerto adjust the current position of the object to the standard position ofthe object with respect to said image capturing means before theprovision of said game is initiated.
 20. The computer readable mediumaccording to claim 9, wherein said guiding comprises guiding the playerto adjust the current position of the object to the standard position ofthe object with respect to said image capturing means before theprovision of said game is initiated.